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Aquaculture: a rapidly growing and significant source of sustainable food? Status, transitions and potential

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The status and potential of aquaculture is considered as part of a broader food landscape of wild aquatic and terrestrial food sources. The rationale and resource base required for the development of aquaculture are considered in the context of broader societal development, cultural preferences and human needs. Attention is drawn to the uneven development and current importance of aquaculture globally as well as its considerable heterogeneity of form and function compared with established terrestrial livestock production. The recent drivers of growth in demand and production are examined and the persistent linkages between exploitation of wild stocks, full life cycle culture and the various intermediate forms explored. An emergent trend for sourcing aquaculture feeds from alternatives to marine ingredients is described and the implications for the sector with rapidly growing feed needs discussed. The rise of non-conventional and innovative feed ingredients, often shared with terrestrial livestock, are considered, including aquaculture itself becoming a major source of marine ingredients. The implications for the continued expected growth of aquaculture are set in the context of sustainable intensification, with the challenges that conventional intensification and emergent integration within, and between, value chains explored. The review concludes with a consideration of the implications for dependent livelihoods and projections for various futures based on limited resources but growing demand.
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Proceedings of the Nutrition Society
The Nutrition Society Summer Meeting 2015 held at University of Nottingham, Nottingham on 69 July 2015
Conference on The future of animal products in the human diet: health and
environmental concerns
Symposium 3: Alternatives to meat
Aquaculture: a rapidly growing and signicant source of sustainable food?
Status, transitions and potential
D. C. Little
1
*, R. W. Newton
1
and M. C. M. Beveridge
1,2
1
Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, UK
2
Fisheries and Aquaculture Department, FAO, Via Delle Terme di Caracalla, 00153 Rome, Italy
The statusand potential of aquaculture is considered as part of a broader food landscape ofwild
aquatic and terrestrial food sources. Therationale andresource base required for thedevelopment
of aquaculture areconsidered in the context of broader societal development, cultural preferences
and human needs. Attention is drawn to the uneven development and current importance of
aquaculture globally as well as its considerable heterogeneity of form and function compared
with established terrestrial livestock production. The recent drivers of growth in demandand pro-
duction are examined and the persistent linkages between exploitation of wild stocks, full life cycle
culture and the various intermediate forms explored. An emergent trend for sourcing aquaculture
feeds from alternatives to marine ingredients is described and the implications for the sector with
rapidly growing feed needs discussed. The rise of non-conventional and innovative feed ingredi-
ents, often shared with terrestrial livestock, are considered, including aquaculture itself becoming
a major source of marine ingredients. The implications for the continued expected growth of
aquaculture are set in the context of sustainable intensication, with the challenges that conven-
tional intensication and emergent integration within, and between, value chains explored. The
review concludes with a consideration of the implications for dependent livelihoods and projec-
tions for various futures based on limited resources but growing demand.
Aquaculture: Fisheries: Nutritional signicance: Resources: Societal impact
Aquaculture, the husbandry and farming of aquatic ani-
mals and plants, has expanded faster in recent decades
than any other livestock sector. It achieved a 7·5%annual
growth rate between 1990 and 2009, eclipsing the rapid
growth rates of the pig (<2·5 %) and poultry (<5 %) sec-
tors
(1)
. In comparison, the overexploitation of wild shery
stocks has led to their contribution to world food stocks
at-lining. Approximately 30 % are overshed, more than
60 % fully shed and <10 % have remaining capacity
(2)
.
In response to expanding demand from growing and better
off populations, the rise of aquaculture has beentimely but
its development has not been evenly distributed nor without
criticism, especially regarding environmental and social
impacts
(1,3,4)
. The characteristics of aquaculture, growing
rapidly from an artisanal and marginal activity, unknown
in most of the World, to a position where there are now
major complementarities and, potentially, resource alloca-
tion conicts with terrestrial livestock and conventional
sheries are reviewed in the present paper. Aquatic pro-
ducts, sh, often remain neglected in the current discourse
regarding food security
(5)
despite its importance in world
trade, human nutrition and support for livelihoods more
broadly. This theme is also explored in the paper.
Why farm? The continuance of wild sheries in seafood
supplies
The motivations for people in traditional societies to
begin farming sh and shellsh are lost in time but an
*Corresponding author: D. C. Little, email dcl1@stir.ac.uk
Proceedings of the Nutrition Society (2016), 75, 274286 doi:10.1017/S0029665116000665
© The Authors 2016
Proceedings of the Nutrition Society
assessment of terrestrial farming may offer some clues.
The agricultural economist Ester Boserup
(6)
would answer
that farming began because it was necessaryor as an-
other observer noted People did not invent agriculture
and shout for joy. They drifted or were forced into it, pro-
testing all the way
(7)
. It was also, likely, a gradual process.
Certainly, the transition from hunting to farming of terres-
trial food occurred over a longer time frame and geog-
raphy than that for aquatic products. A process of
proto-agriculture characterised by an opting in and out
of plant and animal cultivation depending on need, and
coaxing more food out of the environments depending
on need was part of a broader repertoire of responses to
times when demands for wild foods outstripped supplies.
Beveridge and Little
(8)
made a parallel case for the likeli-
hood of such proto-aquaculture occurring in the same
way it has for agriculture. It is clear that aquaculture
began independently and at various times in different
parts of the world and at several points along the aquatic
food supply line, between water and plate. The farming
of sh and shellsh is by denition an activity of settled so-
cieties, originating among both shing and wetland farm-
ing cultures as well as at points of trade. It seems also to
have not been exclusively about food provision;
Beveridge and Little
(8)
found that historically in some con-
texts culture and religion were often powerful motivations
to invest in sh culture and the same has been demon-
strated in some contemporary experience
(9)
.
Since the end of World War II growth of global sh
(sh + shellsh) supplies have outstripped population
growth, effectively increasing annual per capita supplies
from 9·9 kg in the 1960s to 18·4 kg in 2009
(10)
. Growth
has been fuelled by rising demand for livestock and
sh, the result of increased economic access, changes in
trade policies and market liberalisation, urbanisation
and marketing
(11)
. During the rst half of the post-war
period increases in sh supply came from capture
sheries, thanks to massive private and public invest-
ments that resulted in a proliferation of larger, more ro-
bust and increasingly mechanised shing craft and more
effective means of locating, catching and preserving sh
until landed
(12)
. By the late 1970s, however, the majority
of sh stocks was fully or overexploited
(13)
. Today, cap-
ture sheries is dominated in production and employ-
ment terms by small-scale artisanal tropical sheries.
While aquaculture accounted for only 36 % of global
sh supplies in the 1970s in the subsequent decades it
has consistently been among the fastest growing animal
source food sectors, to the extent that one sh in two
now consumed is farmed
(2,4)
. Any future expansion of
supplies must come from aquaculture.
Fisheries currently sustain the livelihoods of more than
40 million full-time and part-time shers directly, an esti-
mated 90 % of whom are small-scale or artisanal and the
balance in industrial sector. Furthermore, an estimated
120 million are supported through sheries-related activ-
ities, through employment in value chains etc. In contrast
more than one-third, or approximately 1 billion people,
are employed in agriculture globally. In poorer counties,
the proportion of employment is higher, reaching 60 % in
sub-Saharan Africa
(14)
.
The phrase the livelihood of last resorthas been
coined for sheries, and the concept of deteriorating
sheries being a poverty trap is supported by recent stud-
ies. Cinner et al.
(15)
identied the poorest shers as the
least likely to exit from a shery in decline, although glo-
bally shing is regarded as a traditional and noble occu-
pation that may be passed down through generations.
Amongst the rural poor, shing activity may decline in
favour of alternative income generating activities but
not cease totally and shers may be especially reluctant
to cease if they have signicant investment in shing ves-
sels and gear
(15)
. The availability of alternative livelihood
opportunities has been recognised as a key step and
aquaculture has been identied as a possible option.
However, this has given variable results, depending on
how lucrative the diversication strategies are in com-
parison with shing. Seaweed farming in the
Philippines, for example, has produced mixed results
(16)
.
Fishing may be preferred because of its ability to provide
occasional very high returns in comparison with activities
such as seaweed farming that are unproven in terms of
providing long-term security. The viability of a small-
scale seaweed culture operation is governed by many of
the same challenges as other small-scale aquaculture
initiatives, including the availability of quality seed
(17)
and access to lucrative markets
(18)
. Seaweed farming
can be particularly labour intensive and there are still
signicant technical hurdles for many species. Sheriff
et al.
(19)
found that the success of grouper and Asian
sea bass cage farming by shers in southern Thailand
was dependent on a number of factors, including access
to credit and the substitution of nancial for natural cap-
ital. The factors that have led to the persistence of
sheries and varied development of aquaculture are
now considered.
Modern emergence of aquaculture: an uneven picture
Opportunity rather than necessity has arguably been the
major driver of modern aquaculture, which only has a
history of four to ve decades with major increases in
the past two decades. Some key exceptions aside, the
rapid growth in aquaculture has been linked as much
to broader, the so-called immanentdevelopment, than
specic innovations
(20)
. Increased human population,
but more importantly increasing wealth and per capita
consumption of sh, especially in wealthier Western
countries, has driven incentives for aquaculture as an en-
terprise at a household and increasingly at the corporate
level. Urbanisation has made self-sourcing impractical
for most, fuelling the trade in sh as a commodity.
Historically sh culture has often been a peri-urban phe-
nomenon, driven by easy access to inputs and mar-
kets
(21)
. In contrast, rural populations in South and
Southeast Asia traditionally secured aquatic products
with little to no effort, as an output of wetland-based
agroecosystems
(22,23)
. Flooded rice-elds produce a
large variety and signicant volumes of aquatic animals
as co-products and efforts to diversify away from rice
monoculture typically resulted in deeper pond areas
(24)
.
Aquaculture: a rapidly growing and signicant source of sustainable food? 275
Proceedings of the Nutrition Society
Smallholder production in such systems
(23)
has
responded to increased demand and seasonal shortfalls,
often evolving into commercially orientated but still
largely household managed systems in Asia
(25)
. These in-
clude shrimp production that has grown strongly in the
past three decades since hatchery juveniles have become
available, in spite of disease-related setbacks. The sector,
dominated by two species, Litopenaeus vanammei and
Penaeus monodon, remains characterised by a large
range of production systems and culture intensities. In
contrast, the farming of Atlantic salmon (Salmo salar),
another global industry, is characterised by its highly
standardised cage-in-coastal water production system.
Growing at an average annual rate of 16 % since 1985,
Norweigan interests dominate globally, producing more
than 50 % of the total harvest in-country
(26)
and with
signicant interests elsewhere (Canada, Chile,
Scotland). Developing international trade for such spe-
cies has driven transformation further and in the case
of salmon led to consolidation of production among
fewer larger enterprises
(26,27)
. Improved productivity of
larger farms, increasing levels of specialisation of produc-
tion and rened regulation have all contributed to con-
solidation, for which there is a general emergent trend
across the seafood sector. Österblom et al.
(28)
identied
thirteen lead rms in the sector, more than half of
which were located in the Asia Pacic region, badging
them as keystone actors because of their analogy to the
disproportionate impact that keystone species in ecosys-
tems exert on ecosystems. These keystone actors cur-
rently control 1116 % of the global marine catch and
1940 % of the most important stocks, including
Alaskan pollock (Gadus chalcogrammus) and various
tunas. The thirteen rms include the top two shmeal
and sh oil producers, 68 % of salmon and 35 % of
shrimp feed producers, as two of the most reliant sectors
on shmeal and sh oil, and therefore exert an inuence
at both ends of the food chain.
Ensuring aquaculture is sustainable or at least respon-
sible has become a key driver for OECD (Organisation
for economic co-operation and development) economies,
particularly in North America and Europe, and private
sector governance where certication, offered by a
range of organisations, has emerged as a major force.
This contrasts with the major centre of production and
consumption, the Asia Pacic region, for which national
and intraregional trade remains largely outside such stan-
dards
(29)
. Production in farmed carps, catsh and tilapias
has grown strongly in this region and probably constitu-
tes more than 80 % of global n-sh aquaculture (Fig. 1).
Growth of major carps and tilapias is especially strong
and is likely to dominate growth into the near future
(Fig. 2). The sustainable intensication of such lower
trophic species, especially in terms of the feed ingredients
used in their diets, warrants at least as much attention as
the critical focus on salmonids and shrimp to date and
this is considered in a later section.
The rapid growth in aquaculture in some parts of the
world suggests that technical barriers can be overcome
given the right context for development and is often
achieved largely by commercial actors. However, recent
history suggests that a pioneer development phase can
occur without signicant levels of conventional research,
as demonstrated by the rapid growth of the striped
catsh (Pangasianodon hypophthalmus) sector in Vietnam
between 2000 and 2008 that outpaced Norwegian salmon
production, with only a fraction of the research and devel-
opment investment (Fig. 3). The recent decline in striped
catsh outputs reects market constraints rather than sign-
icant technical challenges and the sh remains highly
competitive in global white sh markets; investment in re-
search at this point is likely to have impressive returns in
terms of protability. These examples, however, contrast
with those where aquaculture, as either a subsistence or
commercially orientated activity, has developed far more
slowly or indeed has never become established, even
when supported by targeted assistance. A long and disap-
pointing history of promoting subsistence-orientated aqua-
culture in sub-Saharan Africa has been the subject of some
analysis
(30,31)
but aquaculture has generally failed to be
sustained, even where sh has dietary importance, in con-
texts as varied as Sri Lanka to Caribbean and Pacic
Islands
(32,33)
. Failure has been linked to a misunderstand-
ing of demand and, often, a lack of any competitive advan-
tage of start-up aquaculture enterprises with established
sheries. The global aggregate decline in importance of
sheries obscures important local differences. The
European Union continues to rely massively on wild
catches, of which a substantive proportion is imported
(60 % of the overall seafood supply)
(34)
. because of substi-
tution of cheaper products from local sheries and
imported wild and cultured products.
Generalised aquaculture statistics also lead to the
wrong conclusions and disguise its real status. Just as
the aquaculture sector in Europe, with some exceptions,
has failed to grow, double digit growth characterises ex-
pansion in Asia. Drilling further down into the data,
however, shows that Atlantic salmon production is now
more important than beef in Scotland, at least as far as
total farm revenues are concerned
(35)
. Mediterranean sea
bass and bream production has hugely increased in
Turkey, whilst a boom in aquaculture has failed to materi-
alise in some countries in Asia, such as Malaysia, despite
Government support and rapid expansion in neighbouring
countries. More than 65 % of Indonesias massive output
are marine seaweeds, mainly supplying markets for hydro-
colloids (caregeenan) widely used in food processing, al-
though there has also been rapid growth of shrimp,
milksh, tilapia and various catsh (Fig. 4).
Fig. 1. Global aquaculture production by volume in 2014
(42)
.
D. C. Little et al.276
Proceedings of the Nutrition Society
Furthermore, modern aquaculture development can
be characterised as another green rather than a blue revo-
lution, as most sh production occurs inland in fresh-
waters rather than the sea
(36)
. The reality thus
inevitably mutes the expectations of mariculture being
a panacea for food security since a reliance on terrestrial-
ly derived feed ingredients remains, which are heavily
constrained by land and fresh water availability
(37)
. The
exceptions to this normare lter-feeding bivalves and
seaweeds, for which expanded production is not linked
to such constraints but which are still subject to market
and site availability factors.
Thus, the trends in seafood production are more com-
plex than often presented, as are the challenges to aqua-
culture becoming a major source of food and nutrition
where it is most required. An examination of the geog-
raphy of nutritional reliance on seafood can inform our
understanding of its spatial development, to which we
now turn.
The nutritional imperative
Seafood constitutes nearly 16 % of all global animal pro-
tein, more than 5 % of all protein and an estimated 4·5
billion people rely on seafood for 15 % or more of their
animal protein
(5)
. A conventional focus on protein in
diets has undervalued the key importance of fats, espe-
cially the highly unsaturated fatty acids, and micronutri-
ents of which seafood are concentrated sources
(38)
. The
dynamic trade in seafood has raised the issue of emerging
global inequity in terms of continued affordable and
available seafood given current trends
(4)
. The signicant
diversity in current consumption of seafood (as a % of
animal protein) and spatial importance of aquaculture
as characterised by production intensity or contribution
to the economy suggests some important mismatches.
Although high production in South and Southeast Asia
corresponds with this being an area of high consumption,
the swathe of high consumption across west and central
Fig. 2. Growth of major aquaculture n-sh species until 2014 and extrapolated
projections to 2030 (dotted line), millions of tonnes
(42)
.
Fig. 3. Norwegian salmon and Vietnamese catsh production, 20002014 along with
cumulative numbers of peer reviewed articles for each to 2016
(42)
.
Aquaculture: a rapidly growing and signicant source of sustainable food? 277
Proceedings of the Nutrition Society
Africa is yet to be supported by high levels of indigenous
aquaculture, despite high growth since 2000
(2,4,39)
. Wild
stocks, mainly imported cheap marine pelagic species
and local freshwater sheries, currently support most
consumption needs, but intensive aquaculture has now
become established in several areas of West Africa
(40,41)
and imports of farmed sh from China have also
accelerated
(42)
.
In terms of importance to overall economies, aquacul-
ture generally remains <2 % of gross domestic product,
with the exceptions of Bangladesh and Vietnam where,
relative to the economy as a whole, it is highly developed
and important (Fig. 5). The origins of aquaculture in
Asia have been linked to the importance of
aquatic-relative to terrestrial-derived food in densely
settled oodplains and estuarine deltas. Original sites of
aquaculture that have been sustained to the modern era
include the heavily populated river deltas of Southern
China and coastal ponds of Java
(8)
. In contrast popula-
tion densities have increased relatively recently in the
Mekong Delta
(43)
and Bangladesh
(44)
.
The consumption of aquatic v. terrestrial livestock pro-
ducts is a good indicator of their comparative dietary im-
portance and a rapid assessment of the number of food
vendors can be indicative, such as that conducted in
Kolkata (Fig. 6). Expenditure on fresh and preserved
sh exceeded that of all terrestrial meat combined in
one recent study in rural Cambodia
(46)
. In comparison
with terrestrial livestock products, and particularly for
poor consumers, processed forms of aquatic food are
often nutritionally critical. Their importance to food se-
curity through their roles in smoothing seasonality of
food supply and public health are often overlooked, or
perceived as public health risks because of their associ-
ation with parasites and/or adulterants of various
types
(47,48)
. Understanding how farmed and wild sh
full different roles in the diet remains poor; typically,
even in areas where sh culture is well established, farm-
ers and non-producers continue to source and consume
both
(49,50)
. This has implications for livelihoods both
local to, and at distance from, production, and value
chain analysis is increasingly used as the lens to assess
Fig. 4. Aquaculture production in selected Southeast Asian countries in 2004 and 2014
(42)
.
Fig. 5. Global contribution of aquaculture to gross domestic product (GDP) by country
(107)
.
Fig. 6. Proportion of different food stuffs sold at market stalls in
Kolkata, India
(45)
.
D. C. Little et al.278
Proceedings of the Nutrition Society
such impacts
(51)
. It also prompts the issue of differentiat-
ing wild and farmed products, which is considered in the
following section.
Wild and farmed: the linkages
The relationship between wild stocks and farmed aquatic
animals remains closely intertwined. Most products end
up side by side on menus or on seafood displays, some-
times poorly identied or even the subject of fraudulent
claims
(52)
. Some farmed products depend on stocking
juveniles harvested from the wild or at least produced
from breeding animals removed from wild habitats.
Increasingly, farmers have moved towards closed cycle
production, whereby captive bred breeding animals pro-
duce juveniles under controlled conditions and are in-
creasingly the subject of selection, or other hatchery
techniques, to improve their performance. An important
proportion of the global harvest is produced from
so-called enhanced sheries, where natural yields are
increased by stocking hatchery-produced juveniles and
the imposition of management rules
(53)
.
Both fattening of wild juveniles and enhanced sheries
fall between closed cycle aquaculture and exploitation of
wild stocks but tend to target different consumers and
face different challenges.
Some of the worlds most expensive seafood is based
on harvest of wild juveniles before being farmed to a
nished product. Technical control of the whole breeding
cycle for the bluen tuna (Thunnus oreintalis) and
European eel (Anguilla anguilla), despite signicant pro-
gress, have yet to reach commercially viable levels
(54,55)
.
The harvest of juvenile European eels attracts signicant
criticism and, as an endangered species, their harvest has
been made illegal in the European Union. In contrast,
some types of such capture-based aquaculture are widely
perceived as being low impact and sustainable, such as
the collection of spat for on growing of bivalves such
as the blue mussel (Mytilus edulis). In contrast the stock-
ing of hatchery produced juveniles in freshwater
impoundments, rivers and coastal waters, also known
as culture-based sheries, has stabilised or improved ac-
cess to aquatic food for food insecure inland communi-
ties. Marine ranching has had a more mixed impact,
although forming the basis of major processing and ex-
port industries in the West Coast North America and
(canned Pacic salmon).
In contemporary debate, polarised positions are fre-
quently taken whereby aquaculture is framed as sustainable
and in ascent and sheries unsustainable and in decline but
entrenched positions ensure that these are frequently chal-
lenged and that inverse positions are advanced
(3,5660)
.
The sustainable status of aquaculture has often fo-
cused on a narrow Western view of aquaculture based
on mariculture of carnivorous species. Many farmed, es-
pecially the juvenile stages of carnivorous sh, species re-
main dependent on wild sh stocks processed as marine
ingredients (shmeal and sh oil) for feed. As sustainable
catches of the small pelagic species that underpin the
major share of the global resource base have been
reached, marine ingredients represent a declining compo-
nent of most farmed sh diets as feed formulators seek to
substitute them with cheaper plant ingredients and im-
prove the functionality of the replacement products.
The arrival of lower trophic farmed species, which are
generally less dependent on marine ingredients, such as
striped catsh and tilapias, into the international seafood
trade in the last 1015 years has also realigned the sh
in-sh out
(61)
relationship with steep declines in the levels
of marine ingredients commonly used in most aquacul-
ture diets
(61)
. The large differences in dietary dependence
are mostly related to interspecic differences in natural
feeding habit. Fishmeal consumption of farmed
Atlantic salmon still exceeds that of the omnivorous
striped catsh in Vietnam by more than a factor of
ve
(62)
but inclusion levels are dropping quickly for
much of the industry. Innovation towards low and
non-shmeal diets is dynamic, e.g. the recent announce-
ment for a commercial salmon shmeal-free diet.
Innovation of this type is not uniform throughout the
sector, however. From a general but highly inuential
critique of the use of marine ingredients in aquaculture
focusing on salmon and shrimp
(63)
, more recent and
specic analyses have turned to Asia and especially
China
(64)
. Such studies acknowledge progress and oppor-
tunities as well as threats associated with the rapid
growth and changing status of aquaculture.
The nature of the marine ingredients industry has
evolved in parallel with the sheries and aquaculture in-
dustries. All three sectors have had to nd efciency sav-
ings through better utilisation of waste and other
resources, so that now an estimated 35 % of all marine
ingredients are sourced from sheries and aquaculture
by-products that were previously treated as waste
(Marine Ingredients Organisation (IFFO)/University of
Stirling, unpublished results). The role of aquaculture it-
self becoming a major source of marine ingredients and
strategies to enhance their value is considered later.
Delinking aquaculture feeds from marine ecosystems
A decline in reliance on marine ingredients in feed, large-
ly because of their high unit costs, has been a major dri-
ver to change in the aquaculture sector. The increasing
inuence of eco-standards on international trade is also
driving reductions in their use, although sustainability
concerns for terrestrial feed ingredients have attracted
less attention
(65)
. A major challenge is maintaining the
nutritional quality for human consumption of sh in
which vegetables, mainly n-6 oils, have substituted for
marine lipids, mainly n-3 oils
(66)
. A recent consumption
study
(67)
, however, demonstrated that even sh-fed diets
relatively low in sh oil (eco-diets) nonetheless deliver
high nutritional outcomes. Longer term, the use of high
EPA-transgenic Camelina sativa oil may prove a viable
alternative to maintain availability of this vital ingredi-
ent
(68)
, provided it gains acceptance by regulators, retai-
lers and consumers. The search for alternative feed
ingredients continues (see e.g. https://www.foodsofnor-
way.net)
(69)
as for livestock in general, together with
Aquaculture: a rapidly growing and signicant source of sustainable food? 279
Proceedings of the Nutrition Society
improved processing of ingredients and prophylactic
health strategies through use of pro and pre-biotics.
Novel ingredients such as insects show promise, although
this has yet to be demonstrated on a commercial scale
(70)
or gain regulatory approval in key markets. Potentially,
their role in adding value to wastes through production
of a quality feed ingredient can be achieved with minimal
competition for resources. Similarly, the use of waste or
low-value feedstocks for microbial and fungal protein
has resulted in mature technologies and products, some
of which already have full regulatory approval for use
in livestock feeds
(71)
or are already in the marketplace
supporting the move of shrimps away from reliance on
marine ingredients
(72)
. The higher relative interest in
these products by the aquatic rather than the terrestrial
sector reects the formers continued dependence on
high trophic species for marine ingredients. High trophic
aquatic animals have a comparatively high demand for
protein and also face a continuing challenge to inclusion
of high levels of dietary soya. The costs of alternatives
and the risks associated with investment at the necessary
scale are the key constraints to the use of these types of
ingredient
(71)
. Critiques of aquaculture frequently label
it as a high-impact food sector but farmed seafood typic-
ally shares supply chains for feed ingredients with terres-
trial livestock and actually consumes little more than 4 %
of the total used
(1)
. Life cycle assessments underline the
importance of feed to the overall environmental impacts,
including freshwater, land and greenhouse gas emissions
for all livestock, fed-aquaculture included
(37,7377)
to an
extent that in many cases food conversion ratios may
be used as crude indicators of environmental impact.
Innovation to reduce impacts of feeds mostly occurs up-
stream at the levels of ingredient sourcing, production
and processing, but we now turn to environmental inter-
actions in and around the farm.
Environmental challenges at farm and landscape
Expectations that aquaculture would be a novel source of
highly nutritious food, thus relieving pressures on scant
terrestrial resources, have proved to be less revolutionary
than hoped. Like all human activities, aquaculture takes
resources which, using inputs of energy, capital and la-
bour, it transforms into products valued and traded by
society. Impacts may be split into those occurring direct-
ly at the farm and indirect impacts occurring throughout
the value chain, both up and downstream of production.
Aquaculture needs space on land or in coastal waters,
lakes or reservoirs in which to develop production sys-
tems. Water is needed both for physical support of
farmed aquatic animals and to supply oxygen and dis-
perse and assimilate wastes. Seed (spores, spat, post-
larvae, fry or ngerlings) is required to stock the systems,
and fertilisers and feeds must often be used to increase
production. Energy may be required to pump water
and aerate ponds, to import seed and feed onto the
farm and to process and transport produce to markets.
Wastes, uneaten food, faeces and metabolic wastes and
chemicals (including medicines), as well as escaped
organisms (including farm animals and pathogens), are
inevitably released, treated or untreated, into the envir-
onment. Farms, through their physical presence alone,
may also have an effect on ecosystem services and
biodiversity
(66)
.
Water use
The direct and indirect use of water, in contrast to terres-
trial livestock, does not always imply consumption.
Advocates of marine agronomy (marineagronomy.org)
point to the independence of salt tolerant plants from
limited freshwater supplies and the same is true for
lter feeding animals. However, fed n-sh and crusta-
ceans both have varying dependencies on freshwater,
whether grown either in the marine or freshwater envir-
onment related rstly to feed provision and secondly to
environmental services. The water required for the envir-
onmental services; oxygen, support and dispersal of
wastes, remains mostly in the biosphere and may then be-
come unusable for other purposes such as for drinking
but may also be enhanced as a source of nutrition for
integrated agriculture or unaffected for use in indus-
try
(1,66,78)
. How usable it is may depend on the intensity
of aquaculture and the level of subsequent dilution.
Assuming that little water used for environmental ser-
vices is actually consumed
(66)
, it is usually far exceeded
by the amount required for provision of feed
(1,37)
.
Therefore, feed used to edible yield ratio is the key to
overall livestock production ratio and unfed systems,
such as marine molluscs, have a massive advantage
over all fed livestock in terms of freshwater and land
use. However, lter feeders can accumulate toxins from
their surrounding environment and under such condi-
tions require large amounts of energy to clean them
using pure water in depuration processes. In contrast
cage-farmed sh, such as Atlantic salmon, which still
have shmeal and sh oil in their diets do not have
such post-harvest energy demands and have high edible
yield to harvested yield ratios. Shellsh also require
large quantities of energy on site for general maintenance
compared with n-sh
(79)
. Large greenhouse gas emis-
sions related to energy could be mitigated by encour-
aging producers (e.g. reduced costs; tax breaks) to use
cleaner energy, such as from wind and solar technologies.
Intensication of aquaculture
The environmental impacts of aquaculture are largely
determined by species, system, production methods (i.e.
whether extensive, semiintensive or intensive), location
and quality of management. Biodiversity is closely asso-
ciated with the provision of ecosystem services
(39)
. More
product for less environmental impact, while retaining or
improving the high dietary value of farmed seafood and
ensuring high welfare outcomes for both the animals pro-
duced the people involve, are critical components of sus-
tainable intensication
(80,81)
. The environmental
imperative for aquaculture, whereby auto-pollution can
D. C. Little et al.280
Proceedings of the Nutrition Society
undermine productivity at the individual enterprise and
broader, zonal and even global levels of production,
has been a major incentive to rapid change in the sector.
Managing aquatic stocks within the carrying capacity of
the culture environment, well known to terrestrial pastor-
alists, has a particular signicance for a sh farmer need-
ing to maintain both levels of nutrition and water quality
because of the acute impacts of any deterioration in the
latter on the survival and growth of the stock
(80)
.
Access to plentiful water at low-cost and good system de-
sign that allows for removal of solid wastes are critical,
but improvements in feeds and feed delivery that reduce
waste have also been transformative
(78)
. This includes
better nutritional formulation, pellet integrity and feed
systems, all of which have reduced waste and improved
feed efciencies. Simple changes to earthen pond design
have increased productivity by a factor of three in
China, for example
(82)
. Poor solids removal has been a
common cause of failure in highly capitalised intensive
recirculation systems and a major focus for research
(83)
.
Generally, energy efciency increases with intensica-
tion, but access to consistent and affordable power for
aeration or pumping remains a key limitation to cost ef-
fective intensication in many contexts. Tropical coun-
tries may have advantages in their potential for using
solar power in transformations away from fossil-fuel-
based energy. Low- and medium-income countries have
often been less equipped to adapt to volatility in the fossil-
fuel sector
(84)
but there are implications for reliance on
various green energy supplies, including costs and reliabil-
ity. Overall, there are trade-offs between various impacts,
both environmental and social, and recently there have
been efforts to examine these interactions through a
nexusapproach that connects seemingly disparate objec-
tives with food security being the link between them
(85)
.
Aquaculture may compete with or complement agricul-
ture for nutrients, water land and energy. This is often related
to the nature of the aquaculture, particularly if it is integrated
within local food systems or develops as a specialised and
stand-alone activity. Detrimental effects may occur through
intensication of livestock and crop production that can pro-
duce environmental impacts on aquaculture and vice versa.
For example the use of agrochemicals in and around sh
farms or within ricesh systems can have negative impacts
on survival and productivity of both farmed and wild
aquatic animals in receiving waters
(86)
.Management
approaches can be used to mitigate worst impacts and mod-
els of chemical behaviour can guide better practice
(87)
.
Intensive aquaculture, especially if occurring in geographic-
al clusters, can impact on surrounding water quality to the
detriment of both the aquaculture enterprise itself and
other water users
(88)
. Apart from poorer water quality
and its impact on performance, over development can
lead to rapid spread of disease and economic loss
(88)
.
Integrated approaches
A parallel trend to intensication of farmed seafood pro-
duction is integration occurring at different points in the
value chain.
Traditional forms of aquaculture typically developed
under conditions of nutrient scarcity and were often close-
ly integrated with other human activities through neces-
sity
(89)
. A general trend to intensication has rendered
many low-input traditional systems obsolete
(36)
,although
they are being used as templates for reducing the environ-
mental impacts of intensive aquaculture where surplus
nutrients (as wastes and by-products) can be recycled
through associated food production. This is equivalent
to the concept of ecological leftoversadvanced by
Garnett
(90)
as a potential lens for increased sustainability
of livestock production. Central to integrated aquatic pro-
duction is the concept of farming lter feeding (non-fed or
extractive) species alongside fed species, and in some cases
aquatic plants that can take advantage of dissolved nutri-
ents that result from such high-input systems. Typically
the different components are quite separate enterprises,
the sharing of space and nutrients occurring on an infor-
mal or opportunistic basis. Commercial systems exist in
both freshwater and marine contexts, particularly where
they have co-evolved. Such systems are widespread in
coastal China. In recent years the concept, termed
Integrated multitrophic aquaculture
(9193)
has become
the focus of research interest, particularly to mitigate the
environmental impacts of intensive salmonid cage culture.
Challenges remain to ensure the individual components
are economically viable especially within the very different
business enterprise and regulatory contexts of Europe and
North America.
Research into integrated mariculture, targeting the re-
tention and reuse of nutrients, is faced with the challenge
of dealing with saline efuents. Inland aquaculture is
more likely to be integrated with other forms of human
activity, however, either formally or informally.
Scarcity is ensuring that freshwater reuse is becoming in-
creasingly multipurpose, by default. Thus, cages in com-
mon property water bodies enrich water with nutrients
subsequently used for agriculture, and on-farm ponds
act as reservoirs to irrigate subsistence or cash food
crops nearby
(66)
. The practice of livestock waste disposal
in ponds is still common in many parts of the tropics,
even where high-quality sh feeds are available, as it
can reduce costs compared with complete feed-based
production and reduce risks associated with livestock
production. Risks to human health and potentially,
greater greenhouse gas emissions
(94)
, of waste-based
aquaculture need to be considered but both can be dra-
matically reduced through good design. Although use
of formulated diets to intensify production is a clear
trend, retention and in some cases reintroduction of poly-
cultures to produce a range of species in the same pond is
widespread
(95)
. Much of this tendency is related to redu-
cing risks and accessing local markets, although such
practices may also improve water quality and, subse-
quently, productivity gains for the system as a whole.
Whilst returns for the primary species remain critical,
the impacts on local food security of secondary species
harvested from such systems have often been ignored.
Intensication and integration are far from being mu-
tually exclusive. Although farm intensication has often
rendered the ability to horizontally integrate systems
Aquaculture: a rapidly growing and signicant source of sustainable food? 281
Proceedings of the Nutrition Society
more difcult, it has opened opportunities through verti-
cal integration which were not common or efcient in
more traditional systems. The selling of by-products
from sh and shrimp processing is a prime example,
where previously volumes were too low, or products
undervalued, to make this viable, it is now common in
the salmon, tilapia, striped catsh and shrimp industries.
Nevertheless, in contrast to terrestrial livestock, seafood
processing is often linked to export markets, especially
in Asia. The industry for processing seafood by-products
thus still remains underdeveloped compared with its ter-
restrial counterparts.
By-product utilisation
Ultimately, the proportion of the animal that can be uti-
lised as food or indirectly in subsequent value chains is
critical to the overall protability and environmental im-
pact. Markets are well established for all parts of terres-
trial animals, including for example leather, gelatin and
other food additives but less so for aquatic where much
of the by-product may be wasted or poorly utilised.
Where terrestrial animals are most frequently sold as
various portions or cuts, aquatic food may still often be
found sold live or with minimal processing.
Aquaculture itself, particularly through reuse of
by-products of processing, is becoming a major source of
shmeal and oil. The trend is being encouraged by moves
to process sh close to source and making cost effective col-
lection and processing of a wide variety of by-products vi-
able. Hence, for striped catsh in Vietnam, stomachs and
belly aps are used as direct human food locally. New mar-
kets for higher value products, such as collagen and gelatine
extracted from skin before frames and other remains are
processed into lower grade shmeal used for pigs and
other sh production, are emerging
(96)
. Higher value protein
concentrates produced from processing wastes of salmon
and other high-value sh species are being developed for
disease-susceptible juvenile production in both aquaculture
and terrestrial livestock. Functional properties are being in-
creasingly claimed and demonstrated for such products in
both human and animal nutrition
(97100)
.Intheshrimpin-
dustry, chitin from shell by-product is being directed to
manufacture various grades of chitosan that have wide
ranges of applications from waste water treatment to bio-
medical uses. The speed of change in adding value to farmed
seafood is remarkable and signies the sector maturing and
becoming more competitive with other animal products.
Aquaculture and changing impacts on livelihoods
The motivation for developing any aquaculture enter-
prise is increasingly driven by commercial objectives.
Low inputlow output, subsistence orientated aquacul-
ture remains common in some parts of the world, espe-
cially where sh is everyday food, such as in much of
Asia. Households still dependent on agriculture for
much of their income typically use their aquatic resources
as a bankstrategically
(101)
; while selling or gifting some
of their crop they will also continue buying in sh from
the market and/or exploiting wild stocks. These
approaches can offer reasonable income and security at
a lower risk compared with high investments required
for intensication. Opportunities to supply lucrative mar-
kets, however, tends to encourage intensication and at-
tract entrepreneurs to the sector
(25)
, supported by the
development of a range of upstream and downstream ser-
vices. Growth in export-led markets from low- and
medium-income countries-based production, initially
for shrimp and more latterly for white sh species (tilapia
and striped catsh), has often transformed geographical
areas where it is concentrated. Clusters of production
and processing have become relatively prosperous, gener-
ally related to growth in employment opportunities in the
value chain as a whole. Such dynamism can also stimu-
late competition and quality improvement and the rise
of larger-scale commercial aquaculture. Smallholders
may, however, still persist in such contexts, for example
shrimp culture in Thailand, in parallel with company
and corporate development. Private sector standard de-
velopment with its inherent need for traceability is likely
to become a major factor in ensuring access to OECD
markets, although penetration to other markets has
scarcely begun
(29)
. Marginalisation of smaller-scale pro-
ducers and their exclusion from the more lucrative
value chains, such as has occurred in other sectors, is
considered a real threat. Collective action, assisted by dif-
ferent domestic and international organisations, includ-
ing the certiers themselves, offers some hope that
smallholder producers can be retained in such global
value chains, although the speed of consolidation has
been rapid in some sectors. The striped catsh sector in
the Mekong Delta, Vietnam was transformed in less
than a decade from a smallholder system dependent on
local inputs (wild seed, human and pig manure, together
with home-made feeds) supporting local demand, to a glo-
bal producer of white sh, highly dependent on imported
feed ingredients. In general, research suggests that employ-
ment generated by commercially orientated, family farms
is likely to generate the greatest overall opportunities for
rural communities to escape poverty
(25)
. The trend to-
wards the global seafood trade, both wild capture and
aquaculture, being controlled by large integrated corpor-
ate entities is therefore an issue. The resilience of the family
farm, its decline much lamented but still dominant in over-
all food production
(102)
, suggests that the mosaic of con-
temporary aquaculture systems found throughout both
the richer and poorer world will persist.
Conclusions
The expected growth in both human population and per
capita consumption of farmed seafood, is linked to both
the decline in availability of wild stocks and growth in
urban-driven purchasing power. These drivers necessitate
an increase in both the scale and productivity of aquacul-
ture. Already characterised by a huge diversity of farmed
species, consolidation around fewer, genetically
improved strains and species with greater scientic
D. C. Little et al.282
Proceedings of the Nutrition Society
investment is likely in the decades ahead. Life cycle
assessments indicate even current stocks and systems
are comparable with, or better than most terrestrial live-
stock in terms of greenhouse gas, fresh water, land use
and other impacts
(37,77)
. This suggests the untapped po-
tential of aquatic animals has only just begun to be rea-
lised. The rst steps, with selective breeding of farmed
Atlantic salmon, shrimp and tilapias, are well underway
and demonstrating potential, as is consideration of the
benets of the basic efciencies of farming coldblooded
animals. A review of change in basic feeding efciencies
of the key aquaculture species (Table 1) in the past few
years suggests the rapid improvements made, on the
basis of feed, breed and management. This could be
expected to follow similar lines to broiler chicken devel-
opment
(103)
. A key question is where are these major
efciencies most likely to be realised in a constantly mov-
ing food production landscape and the degree to which
the three major pillars of sustainability evolve and impact
on one another?
Current trajectories suggest that international trade in
farmed seafood will remain a key characteristic of the
sector given the advantages that tropical countries have
in terms of species and environments and the trend to-
wards consumption of processed, value-added products
worldwide. Well designed and managed ponds, where en-
vironmental impacts are minimised, have a large com-
petitive edge over more intensive technological
solutions such as tank-based recirculation systems that
have been developed for higher value species in OECD
countries. However, the speciesfarm environment inter-
action is also dependent on consumerslikely choices
going forward and different visions of food futures
(90)
.
The role of technological innovation in meeting the chal-
lenges facing the sustainable intensication of aquacul-
ture have been considered earlier, conventionally
categorised within the elds of feeds, genes and disease
but increasingly advances are being made at their inter-
face and in the context of limitations imposed by the
waternutrientenergy nexus
(104)
.
Financial Support
David Little was supported by the Nutrition Society to
present an oral version of this paper at their Summer
Meeting 2015 at the University of Nottingham. Much
of the article derives from outcomes of the Sustaining
Ethical Aquaculture Trade project (no. 222889)
co-founded by the European Commission within
the Seventh Framework467 ProgrammeSustainable
Development Global Change and Ecosystem for which
consortium members are acknowledged for their partici-
pation. The paper also serves as a contribution to the
FAO Committee on Fisheries Sub-Committee on
Aquaculture, which is working to determine the contri-
bution of aquaculture to food security and nutrition.
Conicts of Interest
None.
Authorship
The concept and major contribution to this article was
prepared by D. L. Contributions to environment sections
and gures were prepared by R. N., while major contri-
butions to development sections were prepared by M. B.
All authors had oversight of the nal document regard-
ing key messages and conclusions.
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3. Moore, D. & Heilweck, M. (2022). Aquaculture: Prehistoric to Traditional to Modern. In: Aquaculture: Ocean Blue Carbon Meets UN-SDGS. (eds D. Moore, M. Heilweck & P. Petros), Chapter 3, pp. 65-95. A volume in the Sustainable Development Goals Series. Springer, Cham. ISBN: 9783030948450. DOI: https://doi.org/10.1007/978-3-030-94846-7_3. 3.1 In this Chapter… It is pointed out that the human tradition of eating shellfish goes back to the time when Homo sapiens first started to migrate out of Africa, between 200,000 and 100,000 years ago. Archaeological finds of ancient meals of shellfish and ancient middens of shellfish shells track human migrations around the world. Middens do more than track migrations. They show that wooden artefacts and plant residues do not survive, but shells do. Illustrating the truth of our fundamental claim that shellfish shells sequester atmospheric carbon permanently. The coastal migrations of early humans continued across the Bering Strait to North America. Early humans along the northwest coast of North America, referred to as First Nations in Canada, actively, and sympathetically, managed the resources of their shoreline habitats, engineering intertidal rock-walled terraces as clam gardens, ancient sustainable mariculture technologies. When we reach recorded history, we enter a phase of increasing exploitation of marine resources for an ever-growing human population. By the end of the nineteenth century oysters had become a cheap staple food on both sides of the Atlantic. The working man could get a decent meal of oysters at any street corner for a few cents in New York or a penny or two in London. The real price we all paid for this was that oyster dredging on both sides of the Atlantic destroyed 85% of the world’s oyster beds. New Yorkers in the 1800s ate about 600 oysters a year each; the average American today eats about 3 oysters each year. Farmed oysters account for 95% of the world’s total present-day oyster consumption. The animal, which has been described as an ecosystem engineer for its reef-building abilities, is one of those that we have driven to the verge of extinction in the wild. In the twenty-first century, the oyster deserves to have the same vigour applied to its restoration and conservation as was applied to dredging it from the seabed during the nineteenth century. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 D. Moore et al., Aquaculture: Ocean Blue Carbon Meets UN-SDGS, Sustainable Development Goals Series. FULL TEXT available from this URL: https://doi.org/10.1007/978-3-030-94846-7_3
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This review paper examines the structure of the EU aquaculture sector, the contribution it makes to the EU economy and the policy environment for past and future development. The primary analysis uses statistical data from the Food and Agriculture Organization of the United Nations which has been re-categorized according to species groups established by the European Aquaculture Technology and Innovation Platform (EATiP) and by culture system type using expert knowledge. Additional data sources for the analysis include the European Market Observatory for Fisheries and Aquaculture Products (EUMOFA) and the European Commission Scientific, Technical and Economic Committee for Fisheries. EU aquaculture production was 1.34 million tonnes in 2012 with a first sale value of €4.76 billion. Shellfish comprised 45 % by volume and 28 % by value; marine fish 30 % by volume and 53 % by value; and freshwater fish 25 % by volume and 19 % by value. The total production volume has actually fallen slightly from 1.4 million tonnes in 2000, whilst the value has increased significantly from 2.79 billion in 2000, mainly due to a growth in Atlantic salmon production. Five countries accounted for around 78 % of the direct output value of EU aquaculture in 2012, the UK, France, Greece, Italy and Spain. Around 50 % of the direct output value was generated using marine cage systems (28 % by volume), whilst less than 3 % of value was generated in recirculated aquaculture systems (<1.5 % by volume). Around 5 % of value was contributed by extensive to semi-intensive inland and coastal pond systems. STECF (2014) estimates there are between 14,000 and 15,000 aquaculture enterprises in the EU employing around 80,000 people, approximately 40,000 full-time equivalent (FTE). The greatest number of jobs (FTE) is provided by the freshwater pond and suspended shellfish sectors due to much lower productivity figures. This could be seen as a social benefit in rural and coastal regions, but corresponding low wages could also discourage young entrants to the industry and lead to dependency on migrant workers. Where efficiencies can be improved through capital investment there is likely to be significant scope for consolidation of ownership as can be observed in the marine fish sector. The output from aquaculture has to find a place within the wider fish and seafood market where volumes are generally inversely related to price. The potential growth of the sector is therefore constrained both in relation to the overall market and with respect to competition from substitute products. These include product from EU capture fisheries as well as imports from third countries (sourced from aquaculture and capture fisheries). Whilst interactions between individual products can be hard to demonstrate, any increase in production costs is likely to lead to lower output volumes, whilst improvements in production efficiency can lead to increased output volumes. With around 60 % of EU fish and seafood supply obtained through imports, and little prospect of increasing outputs from capture fisheries, EU policy is generally supportive of sustainable aquaculture development for reasons of food security and economic development. The underlying basis for this is maximizing the quality and health benefits of farmed products, whilst improving resource efficiency and minimizing impacts. This is expressed through funding support for research and technological development and structural funds to the fisheries and aquaculture industries. However, constraints to growth also exist in the form of regulatory barriers and costs that reduce industry competitiveness. Changing market requirements are also a factor. Prospects for growth have been assessed using the results of EATiP stakeholder workshops combined with the analysis of the sector by system type. These suggest an overall increase in production by 55 % is possible by 2030 based mainly on expansion of marine cage-based farming using larger systems in more exposed sites and similarly shellfish farming using larger-scale suspended systems. Expansion of recirculated aquaculture systems appears likely based on entrepreneurial and European policy for research and technological development activity, although constrained by currently low competitiveness.
Thesis
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This thesis assesses aquaculture’s actual and potential poverty impacts and the institutions required for aquaculture development in Ghana. Data were collected using a survey of 69 small-scale fish farming households and 74 crop farming households in Ashanti Region, a survey of cage farms (19 small and medium enterprises (SMEs) and 2 large-scale farms) in Lake Volta, focus group discussions and key informant interviews. The hypotheses tested are: i) small-scale aquaculture has positive direct poverty impacts; ii) indirect impacts (e.g. economic multiplier effects) from SME development have more poverty reduction potential than direct and indirect impacts from small-scale aquaculture; and iii) aquaculture development requires complementary technical and institutional development. The results suggest that small-scale pond aquaculture increases household income of non-poor farmers who are trained and/or use better management practices (termed fish farming type A). Fish farming type A by non-poor farmers has strong indirect poverty impact pathways and thus, for equivalent increases in scale, higher potential poverty impact than small-scale aquaculture by poor farmers (who have difficulties achieving equivalent productivity), or SME cage aquaculture (where indirect poverty impacts are weaker). However growth of fish farming type A is constrained by high transaction costs and risks. Institutional innovation is thus required to facilitate coordinated value chain development and enable farmers to access services and more lucrative markets. The findings support the current move in aquaculture development away from focusing on poor producers towards a broader value chain perspective and emphasis on developing more commercial aquaculture. This perspective is important due to the benefits of employment generation along value chains and the need for simultaneous and complementary value chain investments for aquaculture system growth. However the findings highlight ambiguities within the emerging paradigm and the need to target aquaculture systems and farmer categories with the highest poverty impact potential in different contexts.
Article
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Following a precise evaluation protocol that was applied to a pool of 202 articles published between 2003 and 2014, this paper evaluates the existing evidence of how and to what extent capture fisheries and aquaculture contribute to improving nutrition, food security, and economic growth in developing and emergent countries. In doing so we evaluate the quality and scientific rigor of that evidence, identify the key conclusions that emerge from the literature, and assess whether these conclusions are consistent across the sources. The results of the assessment show that while some specific topics are consistently and rigorously documented, thus substantiating some of the claims found in the literature, other areas of research still lack the level of disaggregated data or an appropriate methodology to reach consistency and robust conclusions. More specifically, the analysis reveals that while fish contributes undeniably to nutrition and food security, the links between fisheries/aquaculture and poverty alleviation are complex and still unclear. In particular national and household level studies on fisheries’ contributions to poverty alleviation lack good conceptual models and produce inconsistent results. For aquaculture, national and household studies tend to focus on export value chains and use diverse approaches. They suggest some degree of poverty alleviation and possibly other positive outcomes for adopters, but these outcomes also depend on the small-scale farming contexts and on whether adoption was emergent or due to development assistance interventions. Impacts of fish trade on food security and poverty alleviation are ambiguous and confounded by a focus on international trade and a lack of consistent methods. The influences of major drivers (decentralization, climate change, demographic transition) are still insufficiently documented and therefore poorly understood. Finally the evaluation reveals that evidence-based research and policy narratives are often disconnected, with some of the strongest and long-lasting policy narratives lacking any strong and rigorous evidence-based validation. Building on these different results, this paper identifies six key gaps facing policy-makers, development practitioners, and researchers.
Chapter
Around 85% of the world's farmed fish supplies are derived from freshwater production. The ecological impacts associated with this arise from demands on resources (land, water, seed, feed and energy) and the quantities of wastes, including fish farm escapees, released into the environment. Ecological impacts are determined by species, system, production methods (i.e. whether extensive, semi-intensive or intensive), location and quality of management as well as by the nature of the receiving environment. Global-scale analysis shows that freshwater aquaculture has less impact on the environment than that of other animal source foods. Variability among systems is substantial, however, offering significant room for improvement.
Chapter
Aquaculture has been identified as a critical part of supporting food security, especially for low- and medium-income countries (LMIC) in which fish is an established and key part of diets. Finfish and other aquatic products (“fish”) are high in protein and rich in micronutrients. Employment for low-income people throughout aquaculture value chains is increasingly contributing both directly and indirectly to their food and nutritional security.